Can someone explain the difference between minecraft maps and worlds?

I have two Minecraft Bukkit SMP server instances on my host and I understand there's a default "world" included with each instance. I've read about multi-world support in future versions of Bukkit or Minecraft, but at the moment, I believe I'm stuck with a single "map" for each world.

Am I missing something or am I currently limited to a single world (and a single map) on each server?

Solution 1:

AFAIK, there is no difference between "map" and "world."¹

You can generate new maps/worlds for your server by renaming the "world" folder that is in the same directory as your server. When you start your server, it will see that there isn't a world named "world", and will create one.

¹Note: There is now a map object in the game.

Solution 2:

The world is the terrain around you, the actual blocks that make up what you see and interact with. A map is some 2D representation of the world (Aside: This applies to the real world too!). There are already programs to generate a variety of different maps, from straight top-down maps to cave-maps, isometric maps, etc.

In Minecraft 1.6 there will be a new map item which can be crafted to provide top-down mapping functionality in-game.